1. Field of the Invention
This invention relates to a connector for forming fluid-tight connections between the fluid-carrying pipes of an hydraulic system or for connecting one or more such pipes to a fluid pressure-operated unit incorporated in an hydraulic system. The coupling device of the invention is primarily for use with vehicle hydraulic clutch and brake actuating systems.
2. Description of the Prior Art
In conventional vehicle assembly operations, still in widespread use, the individual components of an hydraulic system, such as a clutch system for example, are installed in a vehicle, interconnected by pipes, filled with fluid and bled to remove any entrapped air. Such an installation procedure is time-consuming and therefore expensive, and is by no means ideal for performance on a rapidly moving vehicle assembly line. It is possible to pre-fill individual units, such as master and slave cylinders, and store them until required for use, but the stored units must be sealed against leakage in a manner permitting their subsequent rapid installation and the formation of hydraulic connections without ingress of air. Conventional attepts to achieve this have proved to be unsatisfactory.
In a known proposal, illustrated in British Pat. No. 1132443, a connecting device is used to assemble a pair of pre-filled hydraulic circuit portions of which the ends are sealed by diaphragms, the device including a puncturing element located therein which acts to rupture the diaphragms, during assembly of the circuit portions by means of said device, in order to establish communication between the circuit portions. This proposal is unsatisfactory, in practice, because the inclusion of the internal rupturing device inevitably leads to the entrapment of air and the suggested method of air exclusion, prior filling of the space containing the puncturing device, is unreliable and not suited to the rapid assembly techniques required on a production line.